Bone plate system and method

ABSTRACT

A bone plate system comprises a bone screw and a bone plate having at least two screw-receiving hole structures, at least one of the hole structures comprising an eccentric portion adjacent a first seating area for biasing bone in an inferior fusion area into dynamic compression as the screw is advanced, and a cowl portion that at least partially defines a second seating area and being positioned to enable cross-screw compression of an inferior fusion area. The screw is seatable in either the first or second seating area at the option of a surgeon. A surgical method generally comprises inserting a bone screw into the compression plate and compressing bone in an inferior fusion area by either dynamic or cross-screw compression.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.16/507,630, filed Jul. 10, 2019, which claims the benefit of U.S.Provisional Application No. 62/696,643, filed Jul. 11, 2018, which arehereby incorporated by reference as if fully set forth herein.

TECHNICAL FIELD

This disclosure generally relates to bone plates for use in bone fusionprocedures, and more particularly, to bone plates for fusion of two bonestructures or repair of a bone fracture via bone compression plates.

BACKGROUND

Numerous forms of bone fusion are known in the art. Many plating systemshave incorporated compression features to cause compression of a bonefusion area, by which is contemplated a fracture or joint to be fused.Plates designed for dynamic compression incorporate at least one screwhole at one portion of the plate and a compression slot disposed at adifferent portion of the plate. The compression slot comprises a holewith an eccentric feature that generally is sloped inferiorly towardsthe direction of the other hole. After driving a screw into inferiorbone through the non-compression screw hole, a screw then is driventhrough the compression slot. An inferior side of the head end engagesthe eccentric feature, which thereby creates a camming interactionbetween the screw and the eccentric feature to pull the underlying bonesegments towards one another as the screw travels laterally relativedown the slope of the eccentric feature. As the head of the screw movesto its fully seated position, and with the other screw already drilledin place, the bone fusion area will be compressed via dynamiccompression.

It is also known in the art to employ cross-plate screw compression.With this type of plate, a user places a screw through a plate at atrajectory that allows the screw to reach across the joint or fracturein the inferior fusion area. The plate effectively becomes a largewasher-like structure, such that, as the threads of the screw engage thebone on the far side of the fracture or joint, the advancement of thescrew causes compression across the bone fusion area.

SUMMARY

A bone plate system comprising at least a first bone screw and a boneplate has been devised. The bone plate has at least two screw-receivinghole structures defining respectively a first hole and a second hole. Atleast one of the hole structures includes an eccentric portion adjacenta first seating area, the head of the first screw being shaped to engagethe eccentric portion and via camming action to bias bone in an inferiorfusion area into dynamic compression as the screw is advanced, the firstscrew being positioned at a first orientation when seated in the firstseating area. The same hole structure comprises a hood or cowl portionthat at least partially defines a second seating area. The secondseating area is positioned with respect to the first area such that thefirst screw is positioned at a second orientation when the first screwis seated in the second seating area. The second orientation isdifferent from the first orientation and the first screw is sized toenable cross-screw compression of the inferior fusion area. The firstscrew is seatable in either the first seating area or the second seatingarea at the option of the surgeon. This approach enables the surgeon toselect either dynamic compression or cross-screw compression using thesame bone plate system, depending on the judgment of the surgeon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are representational views of prior art dynamiccompression bone plate systems, FIG. 1 illustrating initial placementand drilling of the screw into a compression slot, and FIG. 2illustrating the screw once advanced to the fully seated position.

FIG. 3 is a representational view illustrating a prior art cross-screwcompression system.

FIG. 4 is a top perspective view of a first bone plate.

FIG. 5 is a top plan view of the first bone plate.

FIG. 6 is a bottom plan view of the first bone plate.

FIG. 7 is a side elevation view of the first bone plate.

FIG. 8 is a cross-sectional view of the first bone plate taken along theline 8-8 of FIG. 4.

FIG. 9 is a cross-sectional view of the first bone plate taken along theline 9-9 of FIG. 4.

FIG. 10 is a side elevation view of a first bone screw.

FIG. 11 is a side elevation view of a second bone screw.

FIG. 12 is a cross-sectional view of FIG. 8 showing a portion of thefirst bone screw of FIG. 10 assembled with the first bone plate.

FIG. 13 is a cross-sectional view of FIG. 8 showing a portion of thesecond bone screw of FIG. 11 assembled with the first bone plate.

FIG. 14 is a perspective view of the first bone plate secured to aplurality of inferior bones.

FIG. 15 is a top perspective view of a second bone plate.

FIG. 16 is a cross-sectional view of the second bone plate taken alongthe line 16-16 of FIG. 15.

FIG. 17 is a perspective view of the second bone plate secured to aplurality of inferior bones.

FIG. 18 is a top perspective view of a third bone plate.

FIG. 19 is a top plan view of the third bone plate.

FIG. 20 is a cross-sectional view of the third bone plate taken alongthe line 20-20 of FIG. 18.

FIG. 21 is a top perspective view of the third bone plate showing thesecond bone screw of FIG. 11 assembled with the third bone plate, andalternatively as indicated by broken lines, the first bone screw of FIG.10 assembled with the third bone plate.

FIG. 22 is a perspective view of the third bone plate secured to aplurality of inferior bones.

FIG. 23 is a top perspective view of a fourth bone plate.

FIG. 24 is a top plan view of the fourth bone plate.

FIG. 25 is a cross-sectional view of the fourth bone plate taken alongthe line 25-25 of FIG. 23.

FIG. 26 is a side elevation view of a portion of the fourth bone plateincluding the first bone screw of FIG. 10 and the second bone screw ofFIG. 11 assembled with the fourth bone plate.

FIG. 27 is a top perspective view of the fourth bone plate showing thesecond bone screw of FIG. 11 assembled with the fourth bone plate

FIG. 28 is a top perspective view of the fourth bone plate showing thefirst bone screw of FIG. 10 assembled with the fourth bone plate.

Terms of orientation and relative position (such as “inferior”) are notintended to limit the position or orientation of the bone plate orsystem described herein.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examplesand other embodiments may take various and alternative forms. Thefigures are not necessarily to scale; some features could be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentinvention. As those of ordinary skill in the art will understand,various features illustrated and described with reference to any one ofthe figures may be combined with features illustrated in one or moreother figures to produce embodiments that are not explicitly illustratedor described. The combinations of features illustrated providerepresentative embodiments for typical applications. Variouscombinations and modifications of the features consistent with theteachings of this disclosure, however, could be desired for particularapplications or implementations.

With reference now to FIG. 1, the bone plate 20 covers the inferior bonefusion area of a patient as illustrated via bone sections 21, 22. Thepatient's bone has a fracture 23. After screwing a first bone screw 25into a first hole 26 and into bone section 21, a driver 27 is used toscrew a second bone screw 28 into the patient's bone section 22 at theother side of the fracture 23. As seen, the inferior portion of thescrew head 30 engages an eccentric ramp surface 32 of the compressionslot 33, causing the plate and screw construct (20 and 25) to pulltowards the compression screw 28, thus creating compression. When thescrew 28 reaches its fully seated position, as shown in FIG. 2, the boneportions 21, 22 abut one another to aid in healing.

As illustrated in FIG. 3, the illustrated screw 40 is driven through theplate 41 and into the inferior fusion area, specifically through boneportions 43, 44 on both sides of the fracture 42. As the screw 40 isadvanced through the second portion 44 of the bone, the bone willretract in the direction of arrows 46, thus again causing abutment ofthe bone portions 43, 44 in the inferior fusion area.

Turning now to FIGS. 4-9, a bone plate 50 with a first hole structure 52is shown. The first hole structure 52 may be referred to as a“combination” hole structure 52, or a “dual mode compression” holestructure.

The bone plate 50 may also include at least one second hole structure.For example, the depicted bone plate 50 includes four locking holestructures 54 disposed through four lobes of the bone plate 50, with thecombination hole structure 52 extending through the bone plate 50between two of the locking hole structures 54. A medial plate region 56may extend between first and second pairs of the locking hole structures54. As used herein, a “medial” plate region may be a body portion (whichmay be an elongated body portion) of a bone plate that is situated nearthe midline or median plane of the bone plate.

The locking hole structures 54 include thread-engaging portions 55,which, in the illustrated embodiment, take the form of broken threads orlugs. Alternatively, these hole structures may include one or moreinterior unbroken threads (not shown). Furthermore, although shown ashaving common interior geometries, the locking hole structures 54 mayhave different interior geometries.

The bone plate 50 may be, for example, a talonavicular fusion platethat, following a surgical procedure, fuses the talus bone of thehindfoot and the navicular bone of the midfoot.

The combination hole structure 52 permits a practitioner to choose amonga plurality of bone screw varieties to be inserted into the combinationhole structure 52. As will be appreciated, a practitioner may opt toorient a first bone screw, such as a dynamic compression screw, at afirst orientation through the combination hole structure 52, or may optto orient a second bone screw, such as an interfragmentary compressionscrew, at a second orientation through the combination hole structure 52that is different than the first orientation.

In this way, the combination hole structure 52 includes a first seatingarea, shown generally at 60, and a second seating area, shown generallyat 62, that is at least partially offset from the first seating area 60.The first seating area 60 is configured to receive a dynamic compressionscrew, and the second seating area 62 is configured to receive aninterfragmentary compression screw. Both seating areas are unthreaded inthis embodiment, although it is contemplated that the combination holestructure may in other embodiments include a threaded or thread-engagingstructure for one or both of the positions of the screw.

More particularly, the combination hole structure 52 includes a rampwall 70, which may be referred to as an eccentric portion, and curvedside walls 72 that extend about at least a portion of the first seatingarea 60 and that may be referred to as generally bowl-shaped curved sidewalls 72.

The curved side walls 72 extends continuously from the ramp wall 70. Theramp wall 70 and curved side walls 72 generally slope inwardly (e.g.,toward a central axis of the combination hole structure 52) as the wallsextend away from an upper surface 74 of the bone plate 50 in a directionof bone screw insertion (e.g., in a direction of the Z axis). In thisway, the ramp wall 70 generally slopes in a direction toward the secondseating area 62, and the curved side walls 72 generally slope towardeach other.

The ramp wall 70 may generally extend about a first axis, which may bereferred to as an insertion axis 80, that extends orthogonal to the X-Yplane. The curved side walls 72 may generally extend about a secondaxis. The second axis, which also extends orthogonal to the X-Y plane,may be referred to as a seating axis 82. As shown, the seating axis 82may be offset from the insertion axis 80; for example, along a directionof the X axis. The curved side walls 72 may cooperate to define agenerally bowl-shaped first seating area 60. In this way, the curvedside walls 72 may taper relative to the seating axis 82, and upperportions of the curved side walls 72 (e.g., proximate the upper surface74) curve about the seating axis 82.

As discussed in greater detail elsewhere herein, the ramp wall 70 andthe curved side walls 72 cooperate to facilitate insertion of a dynamiccompression screw in the first seating area 60.

As shown in FIG. 8, a non-tapering wall 76 (which may be a generallycylindrical wall) extends below one or both of the ramp wall 70 and thecurved side walls 72. More particularly, the non-tapering wall 76includes a portion that extends from the ramp wall 70 to the lowersurface 58 of the bone plate 50. The non-tapering wall 76 furtherinclude portions that extend from the curved side walls 70 to the lowersurface 58 of the bone plate 50.

The bone plate 50 further includes a hood or cowl 90 that at least inpart defines the second seating area 62. At least a portion of the cowl90 is contiguous with the curved side walls 72.

The cowl 90 includes an upper cowl surface 92 and a lower cowl surface94 opposite the upper cowl surface 92. At least a portion of the uppercowl surface 92 is elevated (e.g., in the Z direction) relative to theupper surface 74 of the bone plate 50 proximate the curved side walls72.

The cowl 90 may include a cowl abutment surface 96 that extends betweenthe upper cowl surface 92 and the lower cowl surface 94. The cowlabutment surface 96 extends obliquely relative to one or both of theupper cowl surface 92 and the lower cowl surface 94. The cowl abutmentsurface 96 extends continuously from one or both of the curved sidewalls 72

As shown in FIGS. 7 and 8, the lower cowl surface 94 extends about across-plate axis 100. The cross-plate axis 100 extends obliquelyrelative to one or both of the insertion axis 80 and the seating axis82.

According to one aspect, no structure or portion of the combination holestructure 52 extends below the lower surface 58 of the bone plate 50. Assuch, the lower surface of the bone plate 50 may be disposed adjacent to(e.g., in direct contact with) an inferior bone structure about anentire lower perimeter of the combination hole structure 52.

Referring to FIG. 10, a first bone screw is shown. The first bone screwmay be a dynamic compression bone screw 150. The dynamic compressionbone screw 150 includes a screw head 152 that includes an inferiorportion 154. A shaft 156 of the dynamic compression bone screw 150includes threads 158 that extends along at least half of the length ofthe shaft 156. In another aspect, the threads 158 may extend along lessthan half of the length of the shaft 156.

Referring to FIG. 11, a second bone screw is shown. The second bonescrew may be an interfragmentary compression bone screw 170. Theinterfragmentary compression bone screw 170 includes a screw head 172that includes an inferior portion 174. A shaft 176 of theinterfragmentary compression bone screw 170 includes threads 178 thatextends along less than half of the length of the shaft 176. In anotheraspect, the threads 178 may extend along at least half of the length ofthe shaft 176.

Referring to FIG. 12, the dynamic compression bone screw 150 is insertedinto the first seating area 60. More particularly, the dynamiccompression bone screw 150 is initially inserted along insertion axis80. At this position, the inferior portion 154 of the screw head 152engages the ramp wall 70. As the dynamic compression bone screw 150 isdriven into the bone (e.g., along a direction of the Z axis), theinferior portion 154 slides down the ramp wall 70, and concurrentlyslides horizontally (e.g., along a direction of the X axis) toward theseating axis 82. As such, via camming action between the inferiorportion 154 and the ramp wall 70, the dynamic compression bone screw 150causes relative lateral movement of the underlying bone portions of theinferior fusion area to thereby bring them into abutment with oneanother. Upon installation, at least a portion of the screw head 152 mayextend at least partially beneath a portion of the cowl 90 (e.g.,inferior to the cowl abutment surface 96).

Referring to FIG. 13, the interfragmentary compression bone screw 170 isinserted into the second seating area 62. More particularly, theinterfragmentary compression bone screw 170 is inserted generally alongcross-plate axis 100. Upon installation, the inferior portion 174 of thescrew head 172 engages the cowl abutment surface 96 and at least aportion of the curved side walls 72. Furthermore, upon installation, atleast a portion of the screw head 172 may extend at least partiallybeneath a lower surface 58 of the bone plate 50. In this way, the screwhead 172 may directly engage an inferior bone.

Referring to FIG. 14, in the installed configuration, the bone plate 50extends across the talus bone 180 of the hindfoot and the navicular bone182 of the midfoot. The interfragmentary compression bone screw 170installed in the combination hole structure 52 cooperates withadditional bone screws installed in the locking hole structures 54 tothereby fuse the talus bone 180 and the navicular bone 182.

Turning now to FIGS. 15 and 16, a bone plate 200 with a first holestructure 202 is shown. The first hole structure 202 may generallycorrespond to the first hole structure 52 of FIGS. 4-9, and as such, maybe referred to as a “combination” hole structure 202, or a “dual modecompression” hole structure.

The bone plate 200 may also include at least one second hole structure.For example, the depicted bone plate 200 includes five locking holestructures 204, including four locking hole structures 204 disposedthrough four lobes of the bone plate 200, and the fifth locking holestructure 204 disposed between two adjacent locking hole structures 204.The combination hole structure 202 extends through the bone plate 200between the other two of the locking hole structures 204. The lockinghole structures 204 include thread-engaging portions 205, which, in theillustrated embodiment, take the form of broken threads or lugs.Alternatively, these hole structures may include one or more interiorunbroken threads (not shown). Furthermore, although shown as havingcommon interior geometries, the locking hole structures 204 may havedifferent interior geometries.

The bone plate 200 may be, for example, a naviculocuneiform plate that,following a surgical procedure, fuses the tarsal navicular bone with oneor more of the medial, middle, and lateral cuneiforms.

The combination hole structure 202 may generally correspond to thecombination hole structure 52 of bone plate 50. As such, the combinationhole structure 202 permits a practitioner to choose among a plurality ofbone screw varieties to be inserted into the combination hole structure202. Similar to bone plate 50, a practitioner may opt to orient a firstbone screw, such as the dynamic compression bone screw 150 of FIG. 10,at a first orientation through the combination hole structure 202, ormay opt to orient a second bone screw, such as the interfragmentarycompression bone screw 170 of FIG. 11, at a second orientation throughthe combination hole structure 202 that is different than the firstorientation.

In this way, the combination hole structure 202 includes a first seatingarea, shown generally at 210, and a second seating area, shown generallyat 212, that is at least partially offset from the first seating area210. The first seating area 210 is configured to receive a dynamiccompression screw, and the second seating area 212 is configured toreceive an interfragmentary compression screw.

More particularly, the combination hole structure 202 includes a rampwall 220, which may be referred to as an eccentric portion, and curvedside walls 222 that extend about at least a portion of the first seatingarea 210. The ramp wall 220 and curved side walls 222 generally slopeinwardly (e.g., toward a central axis of the combination hole structure202) as the walls extend away from an upper surface 224 of the boneplate 200 in a direction of bone screw insertion (e.g., in a directionof the Z axis). In this way, the ramp wall 220 generally slopes in adirection toward the second seating area 212, and the curved side walls222 generally slope toward each other.

As shown in FIG. 16, the ramp wall 220 may generally extend about afirst axis, which may be referred to as an insertion axis 230, thatextends in a direction of the Z axis. The curved side walls 222 maygenerally extend about a second axis. The second axis, which alsoextends in a direction of the Z axis, may be referred to as a seatingaxis 232. As shown, the seating axis 232 may be offset from theinsertion axis 230; for example, along a direction of the X axis. Thecurved side walls 222 may cooperate to define a generally bowl-shapedfirst seating area 210. In this way, the curved side walls 222 may taperrelative to the seating axis 232, and upper portions of the curved sidewalls 222 (e.g., proximate the upper surface 224) curve about theseating axis 232.

The bone plate 200 further includes a hood or cowl 240 that at least inpart defines the second seating area 212. The cowl 240 includes an uppercowl surface 242 and a lower cowl surface 244 opposite the upper cowlsurface 242. At least a portion of the upper cowl surface 242 iselevated (e.g., in the Z direction) relative to the upper surface 224 ofthe bone plate 200 proximate the curved side walls 222.

The cowl 240 may include a cowl abutment surface 246 that extendsbetween the upper cowl surface 242 and the lower cowl surface 244. Thecowl abutment surface 246 extends obliquely relative to one or both ofthe upper cowl surface 242 and the lower cowl surface 244.

As shown, the cowl 240 is contiguous with the curved side walls 222.More particularly, the cowl abutment surface 246 extends continuouslyfrom one or both of the curved side walls 222.

The lower cowl surface 244 extends about a cross-plate axis 250. Thecross-plate axis 250 extends obliquely relative to one or both of theinsertion axis 230 and the seating axis 232.

Referring to FIGS. 16 and 17, the cowl 240 and the curved side walls 222cooperate to facilitate insertion of an interfragmentary compressionscrew in the second seating area 212. As such, the interfragmentarycompression bone screw 170 may be inserted into the second seating area212. More particularly, the interfragmentary compression bone screw 170is inserted generally along cross-plate axis 250. Upon insertion, theinferior portion 174 of the screw head 172 engages the cowl abutmentsurface 246.

Alternatively, as discussed, the combination hole structure 202 mayfacilitate insertion of a dynamic compression screw (not shown) throughthe first seating area 210 and into the inferior bone. Moreparticularly, the ramp wall 220 and the curved side walls 222 cooperateto facilitate insertion of a dynamic compression bone screw 150 in thefirst seating area 210. The dynamic compression bone screw 150 may beinitially inserted along insertion axis 230 such that the inferiorportion 154 of the screw head 152 engages the ramp wall 220. As thedynamic compression bone screw 150 is driven into the bone (e.g., alonga direction of the Z axis), the inferior portion 154 slides down theramp wall 220, and concurrently slides horizontally (e.g., along adirection of the X axis) toward the seating axis 232.

In the installed configuration of FIG. 17, the bone plate 200 fuses thenavicular bone 260 and one or more cuneiform bones 262. Moreparticularly, the bone plate 200 extends across the navicular bone 260and at least one of the cuneiform bones 262. The interfragmentarycompression bone screw 170 is inserted through the first hole structure202, and into both the navicular bone 260 and a cuneiform bone 262 tothereby fuse the two bones.

Turning now to FIGS. 18-20, a bone plate 300 with a first hole structure302 is shown. The first hole structure 302 may generally correspond tothe first hole structure 52 of FIGS. 4-9, and as such, may be referredto as a “combination” hole structure 202, or a “dual mode compression”hole structure.

The bone plate 300 may also include at least one second hole structure.For example, the depicted bone plate 300 includes eight locking holestructures 304, including seven locking hole structures 204 disposedthrough seven lobes of the bone plate 300, and an eighth locking holestructure 204 disposed between two adjacent locking hole structures 304.The combination hole structure 302 extends through the bone plate 300between two of the intermediate locking hole structures 304. The lockinghole structures 304 include thread-engaging portions 305, which, in theillustrated embodiment, take the form of broken threads or lugs.Alternatively, these hole structures may include one or more interiorunbroken threads (not shown). Furthermore, although shown as havingcommon interior geometries, the locking hole structures 304 may havedifferent interior geometries.

The bone plate 300 may further include at least one dedicated dynamiccompression hole structure 306.

The bone plate 300 may be, for example, a medial column fusion platethat, following a surgical procedure, fuses the tarsal navicular bonewith a cuneiform bone as well as with a metatarsal bone.

The combination hole structure 302 may generally correspond to thecombination hole structure 52 of bone plate 50. As such, the combinationhole structure 302 permits a practitioner to choose among a plurality ofbone screw varieties to be inserted into the combination hole structure302. Similar to bone plate 50, a practitioner may opt to orient a firstbone screw, such as the dynamic compression bone screw 150 of FIG. 10,at a first orientation through the combination hole structure 302, ormay opt to orient a second bone screw, such as the interfragmentarycompression bone screw 170 of FIG. 11, at a second orientation throughthe combination hole structure 302 that is different than the firstorientation.

In this way, the combination hole structure 302 includes a first seatingarea, shown generally at 310, and a second seating area, shown generallyat 312, that is at least partially offset from the first seating area310. The first seating area 310 is configured to receive a dynamiccompression screw, and the second seating area 312 is configured toreceive an interfragmentary compression screw.

More particularly, the combination hole structure 302 includes a rampwall 320, which may be referred to as an eccentric portion, and curvedside walls 322 that extend about at least a portion of the first seatingarea 310. The ramp wall 320 and curved side walls 322 generally slopeinwardly (e.g., toward a central axis of the combination hole structure302) as the walls extend away from an upper surface 324 of the boneplate 300 in a direction of bone screw insertion (e.g., in a directionof the Z axis). In this way, the ramp wall 320 generally slopes in adirection toward the second seating area 312, and the curved side walls322 generally slope toward each other.

As shown in FIG. 20, the ramp wall 320 may generally extend about afirst axis, which may be referred to as an insertion axis 330, thatextends orthogonal to the X-Y plane. The curved side walls 322 maygenerally extend about a second axis. The second axis, which alsoextends orthogonal to the X-Y plane, may be referred to as a seatingaxis 332. As shown, the seating axis 332 may be offset from theinsertion axis 330; for example, along a direction of the X axis. Thecurved side walls 322 may cooperate to define a generally bowl-shapedfirst seating area 310. In this way, the curved side walls 322 may taperrelative to the seating axis 332, and upper portions of the curved sidewalls 322 (e.g., proximate the upper surface 324) curve about theseating axis 332.

The bone plate 300 further includes a hood or cowl 340 that at least inpart defines the second seating area 312. The cowl 340 includes an uppercowl surface 342 and a lower cowl surface 344 opposite the upper cowlsurface 342. At least a portion of the upper cowl surface 342 iselevated (e.g., in the Z direction) relative to the upper surface 324 ofthe bone plate 300 proximate the curved side walls 322.

The cowl 340 may include a cowl abutment surface 346 that extendsbetween the upper cowl surface 342 and the lower cowl surface 344. Thecowl abutment surface 346 extends obliquely relative to one or both ofthe upper cowl surface 342 and the lower cowl surface 344.

As shown, the cowl 340 is contiguous with the curved side walls 322.More particularly, the cowl abutment surface 346 extends continuouslyfrom one or both of the curved side walls 322.

The lower cowl surface 344 extends about a cross-plate axis 350. Thecross-plate axis 350 extends obliquely relative to one or both of theinsertion axis 330 and the seating axis 332.

Referring to FIGS. 18-21, the cowl 340 and the curved side walls 322cooperate to facilitate insertion of an interfragmentary compressionbone screw 170 in the second seating area 312. More particularly, theinterfragmentary compression bone screw 170 is inserted generally alongcross-plate axis 350. Upon insertion, the inferior portion 174 of thescrew head 172 engages the cowl abutment surface 346.

Alternatively, as discussed, the combination hole structure 302 mayfacilitate insertion of a dynamic compression bone screw 150 through thefirst seating area 310 and into an inferior bone. More particularly, theramp wall 320 and the curved side walls 322 cooperate to facilitateinsertion of a dynamic compression screw in the first seating area 310.As such, the dynamic compression bone screw 150 may be initiallyinserted along insertion axis 330 such that the inferior portion 154 ofthe screw head 152 engages the ramp wall 320. As the dynamic compressionbone screw 150 is driven into the bone (e.g., along a direction of the Zaxis), the inferior portion 154 slides down the ramp wall 320, andconcurrently slides horizontally (e.g., along a direction of the X axis)toward the seating axis 332.

In the installed configuration of FIG. 22, the bone plate 300 fuses thetarsal navicular bone 360 with a cuneiform bone 362 as well as with ametatarsal bone 364. More particularly, the bone plate 300 extendsacross the navicular bone 360, across at least one of the cuneiformbones 362, and across a metatarsal bone 364. The interfragmentarycompression bone screw 170 is inserted through the first hole structure302, and into both the navicular bone 360 and a cuneiform bone 362 tothereby fuse the two bones.

Turning now to FIGS. 23-25, a bone plate 400 with a first hole structure402 is shown. The first hole structure 402 may generally correspond tothe first hole structure 52 of FIGS. 4-9, and as such, may be referredto as a “combination” hole structure 402, or a “dual mode compression”hole structure. In the approach shown, the bone plate 400 includes twocombination hole structures 402 that are spaced apart along alongitudinal axis 408 of the bone plate 400.

The bone plate 400 may also include at least one second hole structure.For example, the depicted bone plate 400 includes nine locking holestructures 404. The locking hole structures 404 include thread-engagingportions 405, which, in the illustrated embodiment, take the form ofbroken threads or lugs. Alternatively, these hole structures may includeone or more interior unbroken threads (not shown). Furthermore, althoughshown as having common interior geometries, the locking hole structures404 may have different interior geometries.

The bone plate 400 may further include at least one dedicated dynamiccompression hole structure 406.

The bone plate 400 may be, for example, a medial column fusion platethat, following a surgical procedure, fuses the tarsal navicular bonewith a cuneiform bone as well as with a metatarsal bone.

The combination hole structure 402 may generally correspond to thecombination hole structure 52 of bone plate 50. As such, the combinationhole structure 402 permits a practitioner to choose among a plurality ofbone screw varieties to be inserted into the combination hole structure402. Similar to bone plate 50, a practitioner may opt to orient a firstbone screw, such as the dynamic compression bone screw 150 of FIG. 10,at a first orientation through the combination hole structure 402, ormay opt to orient a second bone screw, such as the interfragmentarycompression bone screw 170 of FIG. 11, at a second orientation throughthe combination hole structure 402 that is different than the firstorientation.

In this way, the combination hole structure 402 includes a first seatingarea, shown generally at 410, and a second seating area, shown generallyat 412, that is at least partially offset from the first seating area410. The first seating area 410 is configured to receive a dynamiccompression screw, and the second seating area 412 is configured toreceive an interfragmentary compression screw.

More particularly, the combination hole structure 402 includes a rampwall 420, which may be referred to as an eccentric portion, and curvedside walls 422 that extend about at least a portion of the first seatingarea 410. The ramp wall 420 and curved side walls 422 generally slopeinwardly (e.g., toward a central axis of the combination hole structure402) as the walls extend away from an upper surface 424 of the boneplate 400 in a direction of bone screw insertion (e.g., in a directionof the Z axis). In this way, the ramp wall 420 generally slopes in adirection toward the second seating area 412, and the curved side walls422 generally slope toward each other.

As shown in FIG. 25, the ramp wall 420 may generally extend about afirst axis, which may be referred to as an insertion axis 430, thatextends orthogonal to the X-Y plane. The curved side walls 422 maygenerally extend about a second axis. The second axis, which alsoextends orthogonal to the X-Y plane, may be referred to as a seatingaxis 432. As shown, the seating axis 432 may be offset from theinsertion axis 430; for example, along a direction of the X axis. Thecurved side walls 422 may cooperate to define a generally bowl-shapedfirst seating area 410. In this way, the curved side walls 422 may taperrelative to the seating axis 432, and upper portions of the curved sidewalls 422 (e.g., proximate the upper surface 424) curve about theseating axis 432.

The bone plate 400 further includes a hood or cowl 440 that at least inpart defines the second seating area 412. The cowl 440 includes an uppercowl surface 442 and a lower cowl surface 444 opposite the upper cowlsurface 442. At least a portion of the upper cowl surface 442 iselevated (e.g., in the Z direction) relative to the upper surface 424 ofthe bone plate 400 proximate the curved side walls 422.

The cowl 440 may include a cowl abutment surface 446 that extendsbetween the upper cowl surface 442 and the lower cowl surface 444. Thecowl abutment surface 446 extends obliquely relative to one or both ofthe upper cowl surface 442 and the lower cowl surface 444.

As shown, the cowl 440 is contiguous with the curved side walls 422.More particularly, the cowl abutment surface 446 extends continuouslyfrom one or both of the curved side walls 422.

The lower cowl surface 444 extends about a cross-plate axis 450. Thecross-plate axis 450 extends obliquely relative to one or both of theinsertion axis 430 and the seating axis 432.

Referring to FIGS. 25-27, the cowl 440 and the curved side walls 422cooperate to facilitate insertion of an interfragmentary compressionbone screw 170 in the second seating area 412. More particularly, theinterfragmentary compression bone screw 170 is inserted generally alongcross-plate axis 450. Upon insertion, the inferior portion 174 of thescrew head 172 engages the cowl abutment surface 446.

Alternatively, as shown in FIGS. 26 and 28, the combination holestructure 402 may facilitate insertion of a dynamic compression bonescrew 150 through the first seating area 410 and into an inferior bone.More particularly, the ramp wall 420 and the curved side walls 422cooperate to facilitate insertion of a dynamic compression screw in thefirst seating area 410. As such, the dynamic compression bone screw 150may be initially inserted along insertion axis 430 such that theinferior portion 154 of the screw head 152 engages the ramp wall 420. Asthe dynamic compression bone screw 150 is driven into the bone (e.g.,along a direction of the Z axis), the inferior portion 154 slides downthe ramp wall 420, and concurrently slides horizontally (e.g., along adirection of the X axis) toward the seating axis 432.

In an installed configuration, the bone plate 400 fuses the tarsalnavicular bone with a cuneiform bone as well as with a metatarsal bone.More particularly, the bone plate 400 extends across the navicular bone,across at least one of the cuneiform bones, and across a metatarsalbone. The interfragmentary compression bone screw 170 is insertedthrough the first hole structure 402, and into both the navicular boneand a cuneiform bone to thereby fuse the two bones.

The bone plate 400 may receive a multiple compression screws. Forexample, as shown in FIG. 26, the bone plate 400 may receive a dynamiccompression bone screw 150 through a first combination hole structure402, and may receive an interfragmentary compression bone screw 170through a second combination hole structure 402. Other combinations areexpressly contemplated. For example, the bone plate 400 may receive afirst dynamic compression bone screw 150 through a first combinationhole structure 402, and may receive a second dynamic compression bonescrew 150 through a second combination hole structure 402.Alternatively, the bone plate 400 may receive a first interfragmentarycompression bone screw 170 through a first combination hole structure402, and may receive a second interfragmentary compression bone screw170 through a second combination hole structure 402. A bone plate suchas bone plate 400 having multiple combination hole structures 402 may beutilized, for example, when addressing compound fractures.

A kit comprises a bone plate as described herein and at least one bonescrew, the screw being sized to seat in the combination hole and sizedto enable cross-screw compression of an inferior fusion area. The lengthof the screw should be selected to cross the inferior fusion area whenpositioned for cross-screw compression. The length of the screw may begreater than 75% of the extent of the lateral distance between thecenters of the combination hole and an opposing second hole that ispositioned for cross-screw compression. The length may be greater than80%, greater than 85%, greater than 90%, greater than 95%, or greaterthan 100% of this distance. The kit preferably includes additional bonescrews, one screw for each hole in the bone plate. The screws all may beof identical size or the screws for the conventional holes in the boneplate may be sized differently from the screw that is intended for usewith the combination hole. In some embodiments a longer screw may beused for cross-screw compression than for dynamic compression.

In use, a surgeon may determine whether to employ dynamic compression orcross-screw compression and will make the selection of which screwposition to employ accordingly. The surgeon may make this determinationprior to surgery or even during surgery when the surgeon has a betterview of the inferior fusion area. The surgeon may then position a bonescrew in either of the heretofore described positions and orientationsto enable either dynamic or cross-screw compression of inferior bonestructure. The bone plate system may be used to fuse a fracture or tofuse separate bones, or for other suitable purposes.

The bone plates described herein may be made of titanium or any suitablematerial, as may be the screws, and may be manufactured via conventionalmachining operations.

All methods described herein can be performed in any suitable orderunless otherwise indicated herein or otherwise clearly contradicted bycontext. The use of any and all examples, or language describing anexample (e.g., “such as”) provided herein, is intended to illuminate theinvention and does not pose a limitation on the scope of the invention.Any statement herein as to the nature or benefits of the invention or ofthe preferred embodiments is not intended to be limiting. This inventionincludes all modifications and equivalents of the subject matter recitedherein as permitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed by the invention unless otherwise indicated herein orotherwise clearly contradicted by context. The description herein of anyreference or patent, even if identified as “prior,” is not intended toconstitute a concession that such reference or patent is available asprior art against the present invention. No unclaimed language should bedeemed to limit the invention in scope. Any statements or suggestionsherein that certain features constitute a component of the claimedinvention are not intended to be limiting unless reflected in theappended claims. Neither the marking of the patent number on any productnor the identification of the patent number in connection with anyservice should be deemed a representation that all embodiments describedherein are incorporated into such product or service.

1.-18. (canceled)
 19. A bone fusion method comprising: providing atleast a first bone screw and a bone plate, the bone plate having atleast first and second screw-receiving hole structures definingrespectively a first hole and a second hole, at least the first holestructure including: an eccentric portion adjacent a first seating area,a head of the first bone screw being shaped to engage the eccentricportion and via camming action to bias bone in an inferior fusion areainto dynamic compression as the first bone screw is advanced, the firstbone screw being positioned at a first orientation when the first bonescrew is seated in the first seating area; and a cowl portion that atleast partially defines a second seating area, the second seating areabeing positioned with respect to the first seating area such that thefirst bone screw is positioned at a second orientation when the firstbone screw is seated in the second seating area, the second orientationbeing different from the first orientation and the first bone screwbeing sized to enable cross-screw compression of an inferior fusionarea; the first bone screw being seatable in either the first seatingarea or the second seating area; screwing the first bone screw into bonein first orientation or the second orientation.
 20. The bone fusionmethod of claim 19 wherein at least a portion of the head of the firstbone screw engages bone when the first bone screw is seated in thesecond seating area.
 21. The bone fusion method of claim 19 whereinscrewing the first bone screw into bone includes screwing the first bonescrew into bone in the second orientation, a portion of the first bonescrew passing and through a fissure to thereby cause cross-screwcompression of an inferior fusion area
 22. The bone fusion method ofclaim 19 wherein screwing the first bone screw into bone includesscrewing the first bone screw into bone by engaging the eccentricportion and dynamically compressing an inferior fusion area as the screwis advanced.
 23. The bone fusion method of claim 22, further comprising:screwing a second bone screw through the second hole into bone.
 24. Thebone fusion method of claim 19, further comprising: determining whetherto employ dynamic compression or cross-screw compression; whereinscrewing the first bone screw into bone includes screwing the first bonescrew into bone in the first orientation or the second orientationdepending upon the determination.
 25. A bone fusion method comprising:providing at least a first bone screw, a second bone screw, and a boneplate, the bone plate having a hole structure for receiving the firstbone screw for dynamic compression and the second screw forinterfragmentary compression, the hole structure including: asubstantially smooth eccentric portion adjacent a first seating area, ahead of the first bone screw being shaped to engage the substantiallysmooth eccentric portion and via camming action to bias bone in aninferior fusion area into dynamic compression as the first bone screw isadvanced, the first bone screw being positioned at a first orientationwhen the first bone screw is seated in the first seating area, and acowl portion that at least partially defines a second seating area, thesecond seating area being positioned with respect to the first seatingarea such that the second bone screw is positioned at a secondorientation when the second screw is seated in the second seating area,the second orientation being different from the first orientation; andscrewing at least one of the first bone screw through the bone plate inthe first orientation and the second bone screw through the bone platein the second orientation.
 26. The bone fusion method of claim 25wherein the hole structure includes opposing bowl-shaped side walls thatgenerally extend about an insertion axis and a seating axis that isoffset from the insertion axis to guide sliding of the dynamiccompression screw along the substantially smooth eccentric portion fromthe insertion axis to the seating axis.
 27. The bone fusion method ofclaim 25 wherein the hole structure includes side walls having firstwall portions and second, generally bowl-shaped wall portions thatextend upwardly from the first wall portions.
 28. The bone fusion methodof claim 27 wherein the first wall portions are generally planar. 29.The bone fusion method of claim 27 wherein opposing walls of the firstwall portions are generally parallel.
 30. The bone fusion method ofclaim 27 wherein the cowl portion forms an abutment surface that extendscontinuously from the generally bowl-shaped wall portions.
 31. The bonefusion method of claim 25 wherein the cowl portion forms an abutmentsurface that extends obliquely relative to one or both of an upper cowlsurface and a lower cowl surface.
 32. The bone fusion method of claim 25wherein the hole structure forms a continuous width along bottom wall ofthe bone plate between the first and second seating areas.
 33. The bonefusion method of claim 25 wherein the hole structure generally forms anoval along bottom wall of the bone plate from the first seating area tothe second seating area.
 34. The bone fusion method of claim 25 whereinthe cowl portion continuously increases in thickness between an abutmentsurface of the cowl portion and a bottom wall of the bone plate.
 35. Thebone fusion method of claim 25 wherein heads of the first bone screw andthe second bone screw have a common shape for each seating in either thefirst seating area or the second seating area.
 36. The bone fusionmethod of claim 25 wherein the substantially smooth eccentric portion isunthreaded.